Some time ago I received for identification a microscopic preparation of parasites taken, on 11 March 1929, from a flying squirrel (Sciuropterus volans L.) in the neighbourhood of Agraz, Tartar Republic. The preparation mounted in Canada balsam contained one male and two females. Later I examined a rather large collection of flying squirrels in the Division of Mammals of the Zoological Institute of the Academy of Sciences of U.S.S.R. In one jar containing a flying squirrel from Verchoijansk, Yakutia, 67° 33′ N, 133° 51′ E, I found, among the debris on the bottom, a single specimen of the same parasite.